We have used dense SNP based linkage mapping to identify novel loci associated with familial frontotemporal dementia. This work shows linkage overlapping an extant locus on chromosome 9 which we now is understand is also a risk locus for amyotrophic lateral sclerosis, we are now involved in a positional cloning project to determine the underlying genetic mutation in this family. Our ongoing work on dementia with Lewy bodies and Parkinson's disease with dementia primarily focuses on analysis of loci identified in our genome wide association studies in Alzheimer's disease and Parkinson's disease to see if we can tease out the genetic basis of dementia in these disorders which neuropathologically sit between Alzheimer's and Parkinson's disease;further this work has been extended to analyze the effects of genetic risk loci for dementia/parkinson's disease on neuropathology.